[Pw_forum] charge

[Axel Kohlmeyer]

On 7/30/06, JAIME GUSTAVO RODRIGUEZ ZAVALA <jgrz2010 at yahoo.com.mx> wrote:
> Dear PWscf users,
>
> How can I get the charge over each atom?

for that you have to first decide, how to divide up the charge
density between the atoms. there are multiple strategies for that.
the conceptually 'cleanest' approach is probably the method
suggested by bader (atoms in molecules) and there are several
algorithms to do that available. e.g.:

 G. Henkelman, A. Arnaldsson, and H. Jónsson,  A fast and robust
algorithm for Bader decomposition of charge density, Comput. Mater.
Sci. 36 254-360 (2006).

that specific code needs a cube file with the electron density.

note, that with pseudopotentials, you don't have the full electron
density and would need to reconstruct the core density back
into the cube file for more accurate results. for most cases the
valence density is good enough, especially, if you are looking
at trends.

cheers,
    axel.


>
> thank you.
>
>
>
>
>
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-- 
=======================================================================
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
  Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
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If you make something idiot-proof, the universe creates a better idiot.